Digital technology in Theatres

 Digital cinema refers to the use of digital technology to distribute and project motion pictures.

A movie can be distributed via hard drives, optical disks (such as DVDs and Blu-ray Discs) or satellite and projected using a digital projector instead of a conventional film projector. 

Digital cinema is distinct from high-definition television and, in particular, is not dependent on using television or high-definition video standards, aspect ratios, or frame rates. Digital projectors capable of 2K resolution began deploying in 2005, and since 2006, the pace has accelerated (2K refers to images with 2,048 pixels of horizontal resolution). 

4K is simply a description of the resolution these new theater projectors can display. If you have an 1080p HDTV and a Blu-ray player at home, you can enjoy presentations at a 1920 x 1080 pixel resolution. 

This provides you with 1920 horizontal pixels representing a slightly-less-than-2K display. Sony 4K digital projectors display images at up to 4096 x 2160 pixels or just beyond 4K, which is over 4 times what your 1080p display is giving you. And you thought Blu-ray was nice! For reference, not quite half of the movie theaters in the U.S. have made the transition from film projection to digital projection. And those that have are mainly using 2K projectors. 

 For reference see the video below given